var Bat={
	width:100,//球拍宽度，默认100，随难度等级减少
	div:document.getElementById('bat'),
	left:subs(window.getComputedStyle(document.getElementById('bat')).left),
	top:subs(window.getComputedStyle(document.getElementById('bat')).top),
	speed:10,//移速
	init:function(){
		this.left=subs(window.getComputedStyle(this.div).left);
		this.top=subs(window.getComputedStyle(this.div).top);
	},
	moveleft:function(){
		//左移
		this.init();
		if(this.left>0){
			this.div.style.left=this.left-this.speed+'px';
		}else{
			this.div.style.left=0;
		}
	},
	moveright:function(){
		//右移
		this.init();
		if(this.left<360-this.width){
			//360 屏幕宽度
			this.div.style.left=this.left+this.speed+'px';
		}
	}
}
